Adjustable support for hammer drills



Oct. 16, 1951 1, GLENN ADJUSTABLE SUPPORT FOR HAMMER DRILLS Filed April l5, 1948 A/BC , VVE/V702 I JY L. GLENN Patented Oct. 16, 1951 UNITED STATES PATENT OFFICE ADJUSTABLE SUPPORT FOR HAMMER DRILLs 3 Claims.

This invention relates to adjustable supports for holding hammer drills against a structure into which a hole is to be drilled, and for applying pressure to the drill during the operation. Primarily it is especially adapted to drilling holes in ceilings which are more or less remote from the reach of the operator and fortuitously have a oor surface which provides a cooperative abutment against which the forces applied during drilling react.

In ordinary drilling, by use of rotary drills or other boring tools, it is known to use drills which are forced against the work by feed screws or levers which are manually operated to apply the proper pressure thereto. It is also known to provide adjustable supports through which adjustment to compensate for the distance between an abutment and the surface to be drilled may be provided. Securement after adjustment in such instances is usually provided by clamps, or more securely by holes and pins which effect more rigid attachment than do the clamps. These adjustments, however, while amply satisfactory for ordinary drilling, fail under the reaction stresses of hammer drills which cause slipping of the clamps, or distortion under the hammer blows of the more rigid adjusting means which rapidly makes them inoperative where change Of adjustment is necessary.

An additional problem is met -with in that in hammer drills vibratory shocks must be absorbed either by the structure or the person of the operator, and these conditions are accentuated where overhead drilling is done and the reaction of the weight of the body structure of the drill is not available to absorb the larger portion of the reaction shocks. Additionally, overhead drilling makes it advisable to apply the drilling pressure by foot power, leaving the hands free to steady and direct the more or less attenuated structure of the device.

The objects of the present device are:

To provide a simple, emcient and inexpensive support for a hammer drill, which support may be readily adjusted to compensate for distance between an abutment and the structure to be drilled into;

To provide a hammer drill support through which drilling pressure may be applied by foot power;

To provide a support for a hammer drill in which the pressure applying structure is connected through a resilient connector to the pressure originating member.

The means by which the foregoing and other objects are accomplished, and the manner of their accomplishment will readily be understood from the following specification on reference to the accompanying drawing, in which:

Fig. 1 is an elevational View of the support with the pressure applying cable.

Referring now to the drawings in which the Various parts are indicated by numerals: I2 is a base to which a hollow post I4, preferably a length of pipe, is secured as by welding. Slidably disposed in the hollow post I4 is an extension member IS which preferably also is a pipe, and mounted on the upper end of this member is a head I8 which preferably comprises a plate ISA secured to the member I 6 as by welding, an overlying block ISB of the same length and breadth as the plate, and side blocks IBC cooperating to form a channel, the blocks ISB and I 8C being secured to the plate' |8A as by bolts I8D, and preferably being of wood for the absorption of drill shock. Preferably the side blocks are spaced to closely embrace the sides of the handle of the drill I9 which is to be used therewith, and if desired, the channel formed by the blocks ISB and IBC may be lined with an additional shock absorbing liner IBE as of linoleum, the entire channel structure being designably of destroyable nature and intended to be replaced from time to time as disintegration occurs and necessity requires. The drill used with the device forms no part of the present invention and no detail thereof is shown.

The extension member I6 is provided along one side intermediate its length with a series of holes IBA which are adapted for engagement by a hook 20. One side of the post I4 is provided with a longitudinal slot I4A through which the hook may be inserted and engaged with a selected one of the holes IEA and along which it may freely slide. Adjacent the upper end of the post I4 are ears 22 which are rigidly secured to the post as by welding and which extend laterally outward from the post on either side of the slot I4A. The ears support a pin 24 which journals a grooved roller 26 over which is disposed a cable 28 which has one end fastened to the hook 20, extends therefrom over the top of the roller 2B and thence extends downward to a foot lever 3u immediately adjacent the base I2 and is secured to the lever adjacent one side of the post I4. The cable may have inherent resilience, or as shown in Fig. 5, attachment of the cable to the lever be made through a tension spring 32.

Adjacent its bottom end the post I4 is provided with diametrically opposite slots 14B of Width to receive and loosely embrace the sides of the lever 30. The lever 36 is pivotally supported at one end by a pin 34 which is carried by ears 36 secured to and extending upward from the base l2. From the pin the lever extends through the slots I4B of the post, past the connection of.

Y side ISC ofthe/head.

The base l2 of the drill is seated on the floor 40 or other suitableabutment directly below the location of the hole to be drilled and the extenbit 42 engages the surface M to be drilled.

The hook 20 is engaged with the hole IBA accessible through the slot 14A adjacent the lower end of the slot I4A and the device is ready for use. The drill post I4 is steadied by hand and foot pressure is applied on the pedal 38 to hold the drill bit against the work and drilling proceeded with until the hole is completed, pressure is then released, withdrawing the bit, and shift made to other location. 1

It will be especially noted that the foot pressure applied to the pedal 38 is transmitted to the drill bit through the connecting cable 28, and that theresilience of this cable absorbs a considerable portion of the drill reaction. In many instances, however, the amount of vibration absorbed by the cable is insufcientand it Vis necessary to insert the spring 32 or equivalent shock absorber, but whether cable resilience alone or cable and spring'resilience is relied on,

the structure deiinitelyincludes a resilient connector between the pressure applying pedal and the bit.

It will be further noted that irrespective of the amount of extension of the support there is a minimum of change in the position of the foot pedal at the beginning of the operation.

It will further be understood that should a single depression of the foot pedal be insufcient to complete drilling of the hole to suflicient an extension member slidably disposed in said post and extending therefrom, said member terminating in a drill receiving head, and intermediate its length' being provided with a plurality of holes adapted to engage a hook; said post being slotted in adjacency to said base, a foot pedal disposed' through said slot and having one of its ends hingedly secured to said base, and its opposite end portion provided with a pedal plate, a pulley at the upper end of said postY and members carried by said post journalling said pulley, a resilient cable secured to said foot pedal extending to and over said pulley sion member i6 raised by hand until the drill ,20.

4 and terminating in a hook adapted for engagement at option in any one of said holes, said post being slotted below said pulley to permit said hook engagement and hook shift under pedal action.

2. A support, as for a hammer drill, which support includes a base, a hollow post rigidly secured to and extending upward from said base, an extension member slidably disposed in said post and extending therefrom, said member terminating in a drill receiving head, and intermediate its length being provided with a plurality of holes adapted to engage a hook; said post being slotted in adjacency to said base, a foot pedal disposed through said slot and having Vone of its ends hingedly secured to said base, and

`its opposite end portion provided with a pedal plate, a pulley at the upper end of said post and members carried by said post journalling said pulley, a tension spring secured to said foot pedal, a cable secured to said spring, extending to and over said pulley and terminating in a hook adapted for engagement at option in any one of said holes, said post being slotted below said pulley in alinement with said holes to permit said hook engagement and hook shift under pedal action. y

3. A support, as for a hammer drill, which support includes a base, a hollow post rigidly secured to and extending upward from said base, an extension member slidably disposed in said post and extending therefrom, said member terminating in a head which includes a channel of resilient material conformed to receive and embrace slide portions of said drill, said extension intermediate its length being provided with .a plurality of holes adapted to engage a hook;-

said post being slotted in adjacency to said base, a foot pedal disposed through said slot and having one of its ends hingedly secured to said base, and its opposite end portion provided with a pedal plate, a pulley at the upper end of said post and members carried by said post journalling said pulley, a cable secured to said foot pedal extending to and over said pulley, a cable secured to said foot pedal extending to and over said pulley and terminating in a hook adapted for engagement at option in any one of said holes, said post being slotted below said pulley to permit said hook engagement and hook shift under pedal action.

JOY L. GLENN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 298,625 Saunders May 13, 1884 1,004,741 Burkholder Oct. 3, 1911 1,113,531 Ball Oct. 13, 1914 1,286,878 Granger Dec. 3, 1918 1,998,294 Thomas et al Apr. 16, 1935 2,315,196 Gallione Mar, 30, 1943 2,378,869 Shea June 19, 1945 2,405,110 Bullock Aug. 6, 1946 2,444,562 Fried July 6, 1948 FOREIGN PATENTS Number Country Date 5,142 Germany Aug. 29, 1878A 

